The specific rotation of a pure substance is 1.68°.What is the specific rotation of a mixture containing 75% of this isomer and 25% of the (-)isomer?
A)+1.68°
B)0°
C)+1.26°
D)+0.84°
E)+)042°

Question

Quizplus · Accepted Answer

The specific rotation of the mixture is calculated by taking 75% of the specific rotation of the pure substance and subtracting 25% of the specific rotation of the (-) isomer, which is the negative of the pure substance's specific rotation. Thus, (0.75 * 1.68) + (0.25 * -1.68) = +0.84°.

The Specific Rotation of a Pure Substance Is 1